The present invention is directed to any system or systems where microbial populations are specifically utilized for a given purpose. The invention has as its objective the enhancement of these systems to achieve the purpose or purposes with greater efficacy and with minimization of some of the side problems experienced prior to the advent of the present invention.
Bioconversion is a process wherein living organisms are employed to carry out a physical and/or chemical change in a substance. The substance can be natural or man-made. The bioconversion processes to which the present invention is directed include both synthetic and degradative processes. Examples of bioconversion processes include, but are not limited to, fermentations, wastewater treatment, biopolymer production, biomining, and microbially-enhanced oil recovery. Fermentations in this context are defined as the process of microbial production of useful products which are primary or secondary metabolites of microbial origin, such as antibiotics, ethanol, acetone, glycols, organic acids, amino acids, vitamins, antimetabolites, esters, ethers, ketones, aldehydes, flavorings, foods, hormones, enzymes, lipids, alkaloids, surfactants, and gases such as methane. The microbial production process may be either aerobic or anaerobic.
Wastewater treatment is defined as the process by which microbial populations are used to remove and degrade waste substances or a particular chemical or chemicals, generated either by industrial activity or by municipalities, contained in an aqueous environment. This can be achieved by aerobic systems, such as trickling filters, and activated sludge systems, or anaerobic treatment systems.
Biopolymer production is the conversion of substrates by a microbial population to homopolymers or heteropolymers having desired properties. Biomining is the extraction and concentration of mineral elements from ores and rocks, mediated by microorganisms.
Microbial enhanced oil recovery is the process of freeing oil deposits trapped in geologic formations, both subterranean and surface, through the action of microorganisms deliberately introduced into the geologic formation. The microorganisms employed are selected for their ability to reduce the viscosity of the trapped oil, to increase dramatically the pressure in the formation, or to bring about other desired changes to aid in forcing out the trapped oil.
As indicated above, the use of microbial consumption of a substrate(s) for various purposes has been widespread. Because of the technical and commercial success of these applications, whether for waste water treatment or for the production of metabolites through fermentation and the like procedures, the respective industries are continually researching and developing different techniques, microbial populations, substrates, etc. in an attempt to further enhance these applications from both effectiveness and economic points of view.
Such is the case with the present inventors, who have discovered a means of increasing the overall effectiveness of microbial populations' consumption and/or bioconversion of an organic substrate (e.g. toxic chemical), without an attendant increase or decrease in (i) the microbial population itself, and (ii) solid waste production (including but not limited to both sludge and biomass).
With respect to waste water treatment, the process objective is to remove as much waste, or a particular constituent thereof, as possible from the water being treated while producing the least amount of biomass or sludge and/or the most complete elimination as possible of the particular substrate.
Likewise, with the production of metabolites (useful chemicals), it is desirable to achieve as close to total consumption or bioconversion of the substrate as possible, as quickly as possible, with the use of smaller microbial populations (i.e., have energies expended for bioconversion rather than in the reproduction of additional cells) in order to positively affect the economies of the production process.
It is common in systems as described above for a good portion of the cell's energies to be expended in the production of new microbial cells which, if not successful in competing for survival with the other cells, die and thus add to the biomass that must be disposed. More specifically, one can view cellular activities in terms of "bio-economics". In order to obtain maximal proliferation, or at the least subsistence, a cell must maximize its efficiencies so that there is insurance of a niche for its continuing activities.
To maximize its efficiencies, all activities of the cell are intercontrolled and intercommunication is carried out on the molecular level.
Maximum efficiency is selected for daily by competition from other species and environmental pressures. If activities are not optimized the price the species must pay is extinction.
As earlier indicated, in biological waste treatment the process objective is to remove as much waste or a given pollutant from the polluted influent as possible while producing the least amount of biomass or sludge for final disposal. It is believed that the present inventors have discovered a means for accomplishing this as well as enhancing fermentation systems to increase the rate of the process, e.g., the rate of ethanol production from glucose, without the need for high capital expenditures or expensive efforts.
While the present invention has applicability in any process wherein a substrate (chemical) and a microbial population are utilized at appropriate conditions to either produce a desired end product or to change the substrate or chemical to another form, perhaps a more desirable form, the invention will be discussed comprehensively as it pertains to waste treatment. More specifically the invention will be discussed as it pertains and applies to the biodegradation of a specific species of chemical pollutant to reduce the concentration of the pollutant in the waste stream, eliminate or alter the pollutant to a more acceptable, dischargeable form. As is well known, many if not most chemicals are subject to dischargeable limitation by the regulations promulgated by federal, state and sometimes municipal authorities. Accordingly, industrial as well as municipal waste management teams are constantly looking for ways of producing acceptable effluent discharges, in order to comply with the regulations, and, it is hoped, doing so in an economical manner. The present invention is meant to aid in achieving these goals.